Akt对哮喘小鼠肺组织VEGF表达的上调作用

目的探讨在哮喘发病机制中,PKB/Akt对哮喘小鼠肺组织VEGF表达的调节作用。方法BALB/c小鼠30只,按随机数字表法均分为正常对照组、哮喘组、PKB/Akt阻断组,免疫荧光、Western blot方法检测各组小鼠肺组织VEGF的表达。结果免疫荧光结果显示:哮喘组肺组织内VEGF阳性产物的平均光密度(MOD)显著高于正常对照组(P<0.01),而PKB/Akt阻断组与哮喘组相比,上述部位VEGF阳性反应产物的MOD值明显降低(P<0.05)。Western blot结果显示:与正常对照组比较,哮喘组小鼠肺组织内VEGF的IDV( integrated density value)与内参照IDV的比值均明显升高(P<0.01),而PKB/Akt阻断组上述部位IL-1β目标带的IDV与内参照IDV的比值均明显低于哮喘组(P<0.05)。结论在NGF介导的哮喘发病机制中,Akt能上调哮喘小鼠肺组织内VEGF的表达。     

Akt/PKB异常与消化系统肿瘤的研究进展

Akt/PKB信号通路是细胞内信号传导的重要环节,参与腚细胞代谢、生存/凋亡、分化和增殖等过程.细胞内Akt/PKB活性状态依赖于其磷酸化与去磷酸化之间的平衡.蛋白磷酸酶PP2A使Akt/PKB去磷酸化而失活,而Ser/Thr蛋白磷酸酶抑制剂冈田酸(okadaic acid)可以增加活化的Akt/PKB.Akt/PKB信号通路调节异常可见于肿瘤、糖尿病甚至精神分裂症等.肿瘤组织中Akt/PKB活性水平高可以是Akt/PKB信号通路上游调节异常造成的,如P13K亚基或:PTEN的基因突变,或者Akt/PKB基凶扩增造成的.Akt/PKB被认为参与了多种肿瘤的发生、发展及侵袭转移.近年Akt/PKB信号通路正逐渐成为肿瘤发牛机制及治疗的研究热点,本文就Akt/PKB异常与消化系统肿瘤的研究进展作一综述.     

PKB／Akt与卵巢癌

PKB／Akt是一种丝氨酸／苏氨酸蛋白激酶，它是磷脂酰肌醇-3-激酶（phosphoinsitide-3-kinase，PI3K）下游的靶蛋白，是PI3K／AKT信号传导途径的中心环节，此通路参与多种肿瘤的发生发展。PKB／Akt参与调节细胞存活、凋亡、扩增、恶性肿瘤的发生及化疗耐药等。PKB／Akt在卵巢癌中表达增高，它的活化可以抑制卵巢癌细胞凋亡，参与卵巢癌的发生、发展、侵袭和转移。Dan等的研究表明，卵巢癌对顺铂耐药与Akt的过表达和激活有关。本文就PKB／Akt与卵巢癌的关系做一综述。     

TrkA对小鼠过敏性气道反应肺组织Akt/PKB的调节作用

目的 探讨神经生长因子(NGF)受体酪氨酸激酶(TrkA)是否调控丝/苏氨酸激酶(Akt/PKB)磷酸化表达来参与小鼠肺组织过敏性免疫炎性变化。方法 制备卵清蛋白(OVA)致敏的BALB/c小鼠过敏性免疫炎症模型,应用HE肺组织病理染色确定模型成功,采用免疫组织化学、免疫荧光和定量RT-PCR等方法,观察给予TrkA抗体后小鼠肺组织磷酸化Akt(p-Akt)表达变化。结果 p-Akt在过敏性免疫炎症模型小鼠肺组织中表达水平高于正常对照组,TrkA阻断后p-Akt在小鼠肺组织中表达水平明显低于过敏性免疫炎症模型小鼠(p<0.05)。结论 TrkA受体参与NGF介导Akt/PKB传导的小鼠肺部过敏性免疫炎症反应。     

Akt对哮喘小鼠下呼吸道及内脏感觉传入部位IL-1β表达的影响

目的探讨在哮喘发病机制中,PKB/Akt对哮喘小鼠肺组织及C7-T5段脊神经节和相应节段脊髓后角IL-1β表达的调节作用。方法BALB/c小鼠30只,按随机数字表法均分为正常对照组、哮喘组、PKB/Akt阻断组,免疫组织化学检测各组小鼠肺组织及C7-T5节段脊神经节和相应节段脊髓后角IL-1β的表达,Western blot方法检测各组小鼠肺组织及C7-T5节段脊神经IL-1β的表达。结果免疫组织化学结果显示,哮喘组肺、C7-T5段脊神经节和相应节段脊髓后角IL-1β阳性产物的平均光密度值(MOD)显著高于正常对照组(P<0.01);而PKB/Akt阻断组与哮喘组相比MOD值明显降低(P<0.05)。Western blot结果显示:与正常对照组比较,哮喘组小鼠肺、C7～T5段脊神经中IL-1β的IDV(integrated density value)与β-actin IDV的比值均明显升高(P<0.01),而PKB/Akt阻断组明显低于哮喘组(P<0.05)。结论NGF介导的Akt通路的激活可上调IL-1β的表达,介导哮喘气道高反应和炎症反应。     

五味子哮喘汤对哮喘小鼠SIRT1/Akt信号通路及肺功能的影响

目的:探究五味子哮喘汤(Schisandrae-asthma decoction)对哮喘小鼠沉默信息调节因子1(silent in-formation regulator 1,SIRT1)/蛋白激酶B(protein kinase B,PKB/Akt)信号通路及肺功能的影响.方法:BALB/c小鼠随机分为对照组、模型组...     

c-Jun氨基末端激酶选择性抑制剂对哮喘小鼠肺组织IL-8表达的影响

目的探讨c-Jun氨基末端激酶选择性抑制剂(SP600125)对哮喘小鼠肺组织白介素-8(IL-8)表达的影响。方法 30只BALB/c小鼠随机分为对照组、哮喘组和SP600125组,制作哮喘模型及干预处理后,处死小鼠,取肺组织,采用免疫组织化学方法和Western blot方法检测各组小鼠肺组织内IL-8的表达。结果免疫组化结果显示,哮喘组小鼠肺组织IL-8表达的平均光密度值为(0.75±0.12),显著高于对照组(0.25±0.03,p0.01),而SP600125组小鼠明显低于(0.44±0.06,p0.01)哮喘组。Western blot结果显示,哮喘组小鼠肺组织IL-8表达的平均光密度值为(0.51±0.08),显著高于对照组(0.15±0.02,p0.01);而SP600125组与哮喘组相比明显降低(0.29±0.04,p0.01)。结论 c-Jun氨基末端激酶选择性抑制剂能降低哮喘小鼠肺组织IL-8的表达。     

γ-促分泌酶抑制剂对哮喘小鼠肺组织IL-4表达的影响

目的探讨γ-促分泌酶抑制剂对哮喘模型小鼠肺组织白介素-4表达的影响。方法选取30只BALB/c小鼠,随机分为对照组、哮喘组和γ-促分泌酶抑制剂阻断组。免疫组织化学方法和ELISA方法检测各组小鼠肺组织内IL-4的表达。结果哮喘组小鼠肺组织IL-4的表达水平显著高于正常对照组(0.01),但是在应用γ-促分泌酶抑制剂处理后,哮喘组小鼠肺组织IL-4的表达水平显著下调(0.01)。结论静脉注射γ-促分泌酶抑制剂能降低哮喘小鼠肺组织IL-4的表达。     

c—Jun氨基末端激酶选择性抑制剂对哮喘小鼠肺组织IL-2表达的影响

目的探讨c-Jun氨基末端激酶选择性抑制剂（SP600125）对哮喘小鼠肺组织白介素-2（IL-2）表达的影响。方法30只BALB／c小鼠随机分为对照组、哮喘组和SP600125组,制作哮喘模型及干预处理后,处死小鼠,取肺组织,采用免疫组织化学方法和Western blot方法检测各组小鼠肺组织内IL-2的表达。结果免疫组化结果显示,哮喘组小鼠肺组织IL-2表达的平均光密度值为0．76＋0．11,显著高于对照组0．25±0．04,P〈0．01;而SP600125组小鼠肺组织IL-2表达的平均光密度值为0．45±0．08,与哮喘组相比明显降低,P〈0．01。Westernblot结果显示,哮喘组小鼠肺组织IL-2表达的平均光密度值为1．26±0．21,显著高于对照组0．36±0．05,P〈0．01;而SP600125组小鼠肺组织IL-2表达的平均光密度值为0．88±0．11,与哮喘组相比明显降低,P〈0．01。结论c．Jun氨基末端激酶选择性抑制剂能降低哮喘小鼠肺组织IL-2的表达。     

地塞米松对哮喘小鼠肺组织中GPR43表达的调节作用

目的 研究G蛋白耦联受体43(GPR43)在哮喘小鼠肺组织内的表达,同时探讨地塞米松对GPR43表达的影响.方法 30只BALB/C6小鼠随机分为对照组、哮喘组、地塞米松组,每组10只;卵清白蛋白(OVA)致敏和激发建立哮喘小鼠模型;肺泡灌洗液(BALF)细胞计数;HE染色观察各组气道炎症发生及气道结构改变情况;RT-PCR测定各组小鼠肺组织GPR43mRNA的表达变化;免疫组化观察肺中GPR43的表达及定位.结果 哮喘组BALF嗜酸性粒细胞(EOS)与对照组相比明显增高,地塞米松组明显低于哮喘组(P＜0.01);HE染色提示哮喘组气道上皮出现EOS等大量炎性细胞浸润,管壁厚度较对照组明显增加(P＜0.01);RT-PCR结果提示GPR43受体mRNA的表达量在哮喘组最低,与对照、地塞米松组相比有统计学差异(P＜0.01);免疫组化图像分析提示GPR43蛋白表达哮喘组明显降低,与对照组、地塞米松组相比均有显著性差异(P＜0.01).结论 哮喘小鼠肺组织中GPR43表达下降,地塞米松能部分上调其表达,从而减轻气道炎症反应.     

机械张应变诱导蛋白激酶B活化对血管平滑肌细胞迁移的影响

目的研究机械张应变诱导蛋白激酶B活化对大鼠血管平滑肌细胞迁移能力的影响。方法应用FX-4000T细胞应变加载系统,对大鼠血管平滑肌细胞施加牵拉幅度为15%、频率为1Hz的张应变。以Transwell和Westernblot等方法观察张应变作用下蛋白激酶B磷酸化和血管平滑肌细胞迁移能力的变化,以未加载张应变的血管平滑肌细胞为对照组。结果与对照组相比,机械张应变增加细胞中蛋白激酶B磷酸化水平,促进血管平滑肌细胞的迁移;PI3K的特异性抑制剂Wortmannin抑制张应变诱导的蛋白激酶B的磷酸化,降低了血管平滑肌细胞迁移能力。结论机械张应变通过上调蛋白激酶B磷酸化水平促进了血管平滑肌细胞迁移,提示蛋白激酶B信号通路参与机械张应变条件下血管平滑肌细胞迁移过程的信号传导。     

Overexpression of Akt/PKB modulates N‐myristoyltransferase activity in cancer cells

N‐myristoyltransferase (NMT) catalyses the myristoylation reaction. Since NMT activity is elevated in various cancers and activated Akt/PKB leads to cell survival, we were interested in studying if activation of Akt/PKB has any effect on NMT. Overexpression of constitutively active Akt/PKB in HepG2 cells (HepG2‐CA‐Akt/PKB) led to an approximately 50% reduction of NMT compared with parental HepG2 cells. Reduced NMT activity in HepG2‐CA‐Akt/PKB was found to be due to the NMT1 phosphorylation. We determined NMT activity in various human breast cancer cell lines with differing metastatic potentials and pseudo‐normal breast cells (HBL‐100). Tumourigenic or metastatic breast cancer cell lines such as MDA‐MB‐231, MDA‐MB‐435, and Hs 578T displayed reduced NMT activity. Western blot analysis revealed that NMT1 is phosphorylated in these breast cancer cells. Furthermore, patients' breast cancer tissue array revealed strong positivity and high intensity for NMT in malignant breast tissues compared with normal breast cells. A gradation in the NMT staining was observed for grade I, II, and III infiltrating ductal carcinoma breast tissues. These studies demonstrate that overexpression of Akt/PKB results in NMT1 phosphorylation and that NMT1 is phosphorylated in breast cancer cells. Immunohistochemical analysis suggests that NMT may prove to be an added diagnostic biomarker for breast cancer. Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

哮喘豚鼠初级传入神经元ERK的表达及NGF的调节作用

目的　探讨细胞外信号调节蛋白激酶 (ERK)在哮喘豚鼠初级传入神经元 (C7 T5脊神经节 )的表达及神经生长因子 (NGF)对ERK的调节作用。方法　利用免疫组织化学结合显微图像分析 ,研究哮喘豚鼠C7 T5脊神经节活化的ERK免疫反应变化。结果　与对照组相比 ,哮喘组豚鼠活化ERK免疫反应在C7 T5脊神经节神经元核内明显上调 (P <0 .0 1) ,其阳性细胞比率明显高于对照组。Anti NGF组豚鼠活化ERK免疫反应在C7 T5脊神经节神经元的核中明显低于哮喘组 (P <0 .0 1)。结论　C7 T5脊神经节神经元活化的ERK可能参与哮喘的发病过程 ,NGF可上调哮喘豚鼠C7 T5脊神经节神经元活化的ERK表达     

Extracellular HIV-1 Tat protein activates phosphatidylinositol 3- and Akt/PKB kinases in CD4+ T lymphoblastoid Jurkat cells

The biological basis for the pleiotropic activity of extracellular human immunodeficiency virus (HIV)-1 Tat protein on lymphoid T cell survival is not well understood. We have here demonstrated that the addition in culture of 0.1–10 nM Tat protein to 36-h serum-starved lymphoblastoid Jurkat T cells rapidly stimulates the catalytic activity of phosphatidylinositol 3-kinase (PI 3-K). The peak of activation was observed 30 min after Tat addition. Extracellular Tat also stimulated the catalytic activity of the Akt/PKB kinase, a major target of PI 3-K lipid products. Pretreatment of serum-starved Jurkat cells with 100 nM wortmannin (WT) or 10 μM LY294002, two unrelated pharmacological inhibitors of PI 3-K, markedly suppressed the catalytic activity of both PI 3-K and Akt/PKB in Jurkat cells. Moreover, at low concentrations (0.1–1 nM), extracellular Tat showed a small but reproducible protection of Jurkat cells from apoptosis induced by serum deprivation (p < 0.05), while the combination of Tat plus 100 nM WT significantly (p < 0.05) increased the percentage of apoptosis with respect to cells left untreated or treated with Tat alone. Taken together, these data suggest that the anti-apoptotic activity of low concentrations of Tat protein on Jurkat cells is mediated by a PI 3-kinase/Akt pathway.     

哮喘豚鼠下呼吸道MMP-2的表达及NGF的调节作用

目的探讨基质金属蛋白酶-2(MMP-2)在哮喘豚鼠下呼吸道的表达及神经生长因子(NGF)对MMP-2的调节作用。方法应用免疫组织化学方法检测各组豚鼠下呼吸道MMP-2免疫反应的变化。用W estern b lot蛋白印迹方法检测各组豚鼠肺组织NGF和MMP-2的表达。用Luzex-F实时图像分析系统和凝胶成像分析系统分别对结果进行图像分析。结果①免疫组织化学结果显示:豚鼠气道上皮和肺内炎性细胞的MMP-2阳性免疫反应产物的平均灰度值(0-深色,255-浅色),生理盐水组(185.60±4.81、161.47±5.71)与单纯致敏组(184.80±9.64、160.33±4.03)比较没有显著差异(P>0.05);哮喘组(141.93±4.66、129.77±4.07)明显低于生理盐水组和单纯致敏组(P<0.01);哮喘+NGF抗体组(鼻腔吸入NGF抗体,179.73±6.11、150.23±8.13)则明显高于哮喘组(P<0.01)。②W estern b lot结果显示:与生理盐水组和单纯致敏组比较,哮喘组豚鼠肺组织MMP-2和NGF阳性产物的IDV(Integrated Density Value)与β-actin IDV的比值均明显升高(P<0.01),而哮喘+NGF抗体组则明显低于哮喘组(P<0.01),表明NGF可上调MMP-2的表达。结论MMP-2可能是哮喘气道重塑的一种调控因素,NGF诱发MMP-2的表达可能是NGF参与哮喘发病的机制之一,NGF抗体抑制哮喘时下呼吸道MMP-2的表达有可能延缓气道重塑的发生,可能是治疗哮喘的新途径。     

Akt/PKB activation in gastric carcinomas correlates with clinicopathologic variables and prognosis

Akt/protein kinase B (PKB) plays an important role in cell survival. However, the role of Akt in the biology of gastric cancer has not been well studied. We sought to investigate the expression of Akt or phosphorylated Akt (pAkt) in human gastric carcinomas and to analyze the relationship between Akt or pAkt and the clinicopathologic parameters. The expressions of Akt and pAkt were evaluated immunohistochemically in 311 gastric carcinomas using the tissue array method. Akt expression was detected in 74% of the tumors and pAkt expression in 78%. pAkt was highly expressed in the early stage of pTNM (p=0.011). We also found an inverse association between pAkt and lymphatic invasion (p=0.01) or lymph node metastasis (p=0.008). pAkt expression was significantly correlated with a higher survival in patients with stage I carcinomas (p=0.0003). Interestingly, combined evaluation revealed that the group with pAkt-positive and lymph node-negative carcinomas showed a better prognosis than the other groups (p<0.0001). In addition, pAkt was shown to correlate positively with APC (p=0.002) and Smad4 (p<0.0001) expression. These findings suggest that pAkt expression may help to predict the clinical outcome of gastric cancer patients.     

哮喘豚鼠MMP-9、TIMP-1免疫反应的变化及与气道重塑的关系

目的　观察实验性哮喘豚鼠气道平滑肌基质金属蛋白酶 9(MMP 9)及其抑制剂 (TIMP 1)的表达以及气道平滑肌厚度的变化。方法　用免疫组织化学结合显微图像分析测定气道平滑肌MMP 9、TIMP 1免疫反应的变化及气道平滑肌厚度。结果　MMP 9、TIMP 1广泛分布于气道平滑肌。哮喘组MMP 9平均灰度值(10 5 94± 6 0 9)明显低于对照组 (12 0 2 5± 3 6 6 ) (P <0 0 1) ;哮喘组TIMP 1平均灰度值 (99 36± 5 71)明显低于对照组 (12 3 4 5 7) (P <0 0 1) ;哮喘组气道平滑肌厚度 (6 45± 1 83μm2 / μm)明显高于对照组 (3 17± 0 85 )(P <0 0 5 )。结论　MMP 9、TIMP 1可能参与哮喘时气道重塑。